EP4003191B1 - Intra-aneurysm device - Google Patents

Description

Technical field of the invention

The invention relates to the field of intra-aneurysmal medical devices. More specifically, the invention relates to intra-aneurysmal flow diversion devices.

Technical background

An aneurysm is a dilation of the wall of an artery. The dilation causes an aneurysmal pocket that communicates with the artery through a narrowed area known to practitioners as the "neck".

The rupture of an aneurysm, or more precisely of the aneurysmal sac, can have serious consequences, including death. Several factors are at the origin of aneurysms. It should be noted that elderly people have a higher prevalence. In these people, the risk of rupture is also greater, particularly due to related pathologies such as high blood pressure, which manifests itself in the form of an increase in blood pressure.

It is therefore a public health problem that needs to be addressed. There are different techniques for treating an aneurysm.

Among the techniques for treating an aneurysm, the so-called "endovascular" technique is distinguished from other techniques by the fact that it includes a step of treating the aneurysm using an endovascular device. In this case, the aneurysm is approached by following the path of the arteries. A carrier catheter (of an intra-aneurysmal device) is introduced through the arteries and directed under radioscopic control. This can also be an extra-aneurysmal device, intra-aneurysmal device or both. The device is then deposited in the aneurysm. In particular, the device is deposited in the artery carrying the aneurysm in the case of an extra-aneurysmal device or in the aneurysm in the case of an intra-aneurysmal device. This helps isolate the aneurysm from the blood flow of the artery to prevent the aneurysm sac from rupturing under blood pressure.

The implementation of this technique can prove particularly complex depending on the technique used for the design of the device but also the structure and shape of the device, even more so when this device is of the intra-aneurysmal type.

There are two techniques for designing cerebral endovascular devices.

A first technique is called "laser cut". The expression "laser cut" according to Anglo-Saxon terminology designates a laser cutting process. It consists of cutting a tube of a shape memory alloy with a laser to create a network of open or closed cells of generally parallelepiped shape. However, the devices manufactured using this technique suffer from sagging due to the curvatures of the artery, which, in addition to representing a danger for the patient, requires, in the long term, a new intervention on the patient in order to be able to replace them. However, since these interventions are very heavy for the patient, it is advisable to limit their number.

A second technique called "braided" consists of creating a braided structure from one or more wires of a shape memory alloy so as to form a network of closed cells. This technique, unlike the first technique described above, makes it possible to design repositionable, flexible devices with a more stable structure, which allows their permanent installation at the level of the artery to be treated. Devices manufactured using the braided technique are classically tubular in shape. They can be used to treat many other pathologies.

However, the use of the braided technique for the design of intra-aneurysmal devices remains very limited, and for good reason; although the use of the braided technique is well suited to the design of devices with simple shapes to produce, for example tubular, it is much less suitable for that of devices with more complex shapes that require specific manufacturing tools and whose manufacturing time can be particularly long. The loop-shaped structure resulting from the configuration of the aneurysm in relation to the artery, as well as the presence of bifurcations in the immediate vicinity of the aneurysm, make the use of the braided technique for the design of intra-aneurysmal devices less common, without however excluding its use.

Among the braided techniques are contour devices. These devices include a head for insertion into the aneurysm and forming a braided structure made of a plurality of wires. The head includes a nodal end at which the wires are crimped and a distal end at which the wires "travel back and forth", such as loops. The wires extend uninterrupted at the loops and are only connected to each other at the nodal end. In addition to the ring required to crimp the wires at this nodal end, a very large number of wires are required to ensure the structural stability of the contour devices. These devices are therefore very bulky and access to certain aneurysms located far in the arteries is complicated or even impossible.

Among the braided techniques, there are "coils". The expression "coils" is an English term designating a small metal spiral used to allow the occlusion of a vessel. Indeed, many intra-aneurysmal devices use coils to fill the aneurysmal pocket of the aneurysm to be treated in order to limit the flow of blood towards the dome and therefore the aneurysm. The operation to fill the aneurysmal pocket with coils is called "coiling". This operation can be relatively long since the entire aneurysmal pocket must be filled for the device to be fully functional.

For example, the document WO2018/130624A1 describes a flow diversion aneurysm device. In addition, the document US2002/198561 A1 describes a method for forming intravascular devices from resilient metal fabric. Additionally, the document WO 2006/052322 describes another example of an intra-aneurysmal device with a braided coil structure. The disclosed intra-aneurysmal device comprises a stent allowing the device to be anchored in a source artery, carrying the aneurysm. Stent is an English term commonly used in the medical field to designate a tube of substantially circular section. Anchoring is done by endothelialization of the stent on the internal wall of the artery. The device comprises a head, generally in the form of a dome intended to be housed inside the aneurysmal pocket. Between the dome and the stent, the device further comprises a thinned intermediate portion which delimits the dome and the stent.

However, the deployment time of this device is very long and the structure is not stable enough to allow its deployment in a shorter time.

Summary of the invention

The invention is defined in independent claim 1. Some optional features of the invention are defined in the dependent claims. An object of the invention is to solve at least one of the above-mentioned problems

For this purpose, an intra-aneurysmal device is provided for treating an aneurysm, comprising a braided, mesh structure made with a plurality of threads, the braided structure comprising a head intended to be inserted into the aneurysm, the head being capable of significantly reducing blood flow in the aneurysm, said head having a dome shape.

The device is characterized in that the braided structure comprises at a proximal end of said braided structure a knot connected to the head and in that, at its distal end opposite said proximal end, the head is formed from ends of wires, at least some of which are mechanically linked together, the ends of the mechanically linked wires being parallel and linked two by two.

The device according to the invention is thus configured so as to be able to be transported to the affected area by means of a micro-catheter whose dimensions are much smaller than those of the device without this being detrimental to the hold. structural head whose dimensions are larger than those of the micro-catheter since it is intended to be inserted into the aneurysm.

Indeed, the fact that the braided structure comprises at a proximal end of said braided structure a knot connected to the head and that, at the distal end of said braided structure, the head is formed of ends of wires, at least some of which are mechanically linked together, makes it possible to preserve the structural strength of the head and to improve the structural stability of the device during the deployment phase. Indeed, this avoids the structural deformation of the device and the separation of the wires from each other which would occur during passage through the microcatheter. Once the device is correctly positioned within the aneurysm, the deployment phase is complete and the device is immediately functional. No additional time is necessary for any filling of the aneurysm pocket as is the case with coil-type devices.

In addition, the device according to the invention has a very small footprint, which allows it to be implanted further into the affected arteries and allows it to treat a greater number of aneurysms. This is due on the one hand to the fact that the knot connected to the head is formed by the braided structure itself, which avoids necessarily having to use a ring, and on the other hand to the fact that some of the ends of the wires being mechanically linked together at the end of the head opposite the knot, the structural stability of the device is due to these connections and not to the number of wires, which can then be very reduced.

• les mailles de la structure tressée sont plus denses au niveau de l'extrémité proximale de ladite tête qu'au niveau de l'extrémité distale de ladite tête ;
• la tête présente une géométrie sensiblement demi-sphérique tournée vers l'extérieur, l'extrémité distale de ladite tête présentant une section sensiblement circulaire de diamètre D2 ;
• le noeud présente une section sensiblement circulaire dont un diamètre D3 est inférieur au diamètre de la tête D2 ;
• le nombre de fils est compris entre 4 et 250 de préférence compris entre 16 et 32 ;
• les fils présentent un diamètre compris entre 10 µm et 500 µm ;
• les fils se superposent au niveau de zones d'intersection ;
• lesdits fils sont liés mécaniquement au niveau desdites zones d'intersection ;
• certaines au moins des extrémités de fils sont liées mécaniquement entre elles par l'intermédiaire d'une portion de liaison faite d'une partie d'un premier fil et d'une partie d'un deuxième fil ;
• les fils sont en matériau biocompatible de préférence du nitinol, platine ou titane ;
• au moins un fil est radio-opaque ;
• le dispositif comprend une portion proximale et destinée à positionner le dispositif ;
• ledit noeud relie la portion proximale à la tête ;
• les mailles de la structure tressée au niveau du noeud sont plus denses que les mailles de la structure tressée au niveau de l'extrémité proximale de la tête ;
• ledit noeud est formé par une bague de sertissage reliant des extrémités de fils entre elles ;
• ledit noeud est formé par des extrémités de fils 6c soudées entre elles.

According to different characteristics of the invention which may be taken together or separately:

• the meshes of the braided structure are denser at the proximal end of said head than at the distal end of said head;
• the head has a substantially semi-spherical geometry facing outwards, the distal end of said head having a substantially circular section of diameter D2;
• the node has a substantially circular section with a diameter D3 less than the diameter of the head D2;
• the number of threads is between 4 and 250, preferably between 16 and 32;
• the wires have a diameter between 10 µm and 500 µm;
• the wires overlap at intersection areas;
• said wires are mechanically linked at said intersection zones;
• at least some of the wire ends are mechanically connected to each other by means of a connecting portion made of a part of a first wire and a part of a second wire;
• the wires are made of biocompatible material, preferably nitinol, platinum or titanium;
• at least one thread is radiopaque;
• the device comprises a proximal portion and intended to position the device;
• said node connects the proximal portion to the head;
• the meshes of the braided structure at the knot are denser than the meshes of the braided structure at the proximal end of the head;
• said knot is formed by a crimping ring connecting wire ends together;
• said node is formed by ends of wires 6c welded together.

Brief description of the figures

• [Fig. 1] la figure 1 illustre une vue en perspective d'un dispositif selon un premier mode de réalisation de l'invention ;
• [Fig. 2] la figure 2 illustre une vue en perspective d'un dispositif selon un second mode de réalisation de l'invention ;
• [Fig. 3a] La figure 3a illustre une vue latérale du dispositif durant la phase d'initiation de son déploiement au sein de l'anévrisme ;
• [Fig. 3b] La figure 3b illustre une vue en perspective du dispositif durant la phase d'apposition sur les parois de l'anévrisme ;
• [Fig. 3c] La figure 3c illustre une vue en perspective du dispositif durant la phase finale de son déploiement au sein de l'artère ;
• [Fig. 4] La figure 4 illustre une vue de face du dispositif selon l'invention après déploiement au sein d'une artère reconstituée ;
• [Fig. 5] La figure 5 illustre le résultat d'une simulation numérique de déploiement du dispositif selon l'invention en vue de face ;
• [Fig. 6a] La figure 6a illustre une vue rapprochée du dispositif selon l'invention lors du procédé de liaison des extrémités des fils selon une première variante ;
• [Fig. 6b] La figure 6b illustre une vue rapprochée du dispositif selon l'invention lors du procédé de liaison des extrémités des fils selon une deuxième variante ;
• [Fig. 6c] La figure 6c illustre une portion de liaison du dispositif de la figure 6a ;
• [Fig. 6d] La figure 6d illustre une portion de liaison du dispositif de la figure 6b ;
• [Fig. 7] La figure 7 illustre un procédé de liaison des extrémités des fils ;

Other objects and characteristics of the invention will appear more clearly in the description which follows, made with reference to the appended figures, in which:

• [ Fig. 1 ] there figure 1 illustrates a perspective view of a device according to a first embodiment of the invention;
• [ Fig. 2 ] there figure 2 illustrates a perspective view of a device according to a second embodiment of the invention;
• [ Fig. 3a ] There Figure 3a illustrates a side view of the device during the initiation phase of its deployment within the aneurysm;
• [ Fig. 3b ] There figure 3b illustrates a perspective view of the device during the apposition phase on the walls of the aneurysm;
• [ Fig. 3c ] There figure 3c illustrates a perspective view of the device during the final phase of its deployment within the artery;
• [ Fig. 4 ] There figure 4 illustrates a front view of the device according to the invention after deployment within a reconstituted artery;
• [ Fig. 5 ] There figure 5 illustrates the result of a digital simulation of deployment of the device according to the invention in front view;
• [ Fig. 6a ] There Figure 6a illustrates a close-up view of the device according to the invention during the method of connecting the ends of the wires according to a first variant;
• [ Fig. 6b ] There Figure 6b illustrates a close-up view of the device according to the invention during the process of connecting the ends of the wires according to a second variant;
• [ Fig. 6c ] There figure 6c illustrates a connecting portion of the device of the Figure 6a ;
• [ Fig. 6d ] There figure 6d illustrates a connecting portion of the device of the Figure 6b ;
• [ Fig. 7 ] There figure 7 illustrates a method of bonding wire ends;

Detailed description of the invention

In reference to the figure 1 , the invention relates to an intra-aneurysmal device 1 for the endovascular treatment of an aneurysm 2. In other words, the device 1 according to the invention is suitable and intended to be implanted within said aneurysm 2. The device 1 as illustrated in figure 1 is at rest.

It is recalled that an aneurysm results from the dilation of the wall of a blood vessel. This vessel is typically an artery. The dilation causes an aneurysmal pocket 8 which communicates with the artery thanks to a narrowed area known to practitioners as the "neck".

The aneurysm 2 in question can have any morphology. It can be an aneurysm with a wide neck or not. The same is true for the carrier vessel which can have very varied dimensions depending on the part of the body concerned, other factors being taken into account.

In addition, the aneurysm 2 in question can be located in any part of the body that has an affected vessel. For example, it can be located in the aorta, making it an aortic aneurysm. It can also be located in an artery of the brain, making it a cerebral or intracranial aneurysm. Cerebral aneurysms are often difficult to access, which makes the deployment of an endovascular device and therefore their treatment by endovascular route particularly complex or even impossible to carry out in certain cases. As will be seen in the following sections, the intra-aneurysmal device 1 according to the invention is particularly well suited to the treatment of cerebral aneurysms due to its easy deployment and its small size.

The intra-aneurysmal device 1 is more particularly a flow diversion device. Devices of this type are distinguished from coil and intra-aneurysmal cage devices essentially in that the treatment of the aneurysm is not done by filling the aneurysmal pocket with coils or with embolization material, as the case may be, but by treatment of the artery carrying the aneurysm.

The device 1 according to the invention comprises a head 5 forming a braided structure S, with mesh, made with a plurality of wires 6.

The head 5 is intended to be inserted into the aneurysm 2. Its function is to significantly reduce the blood flow in the aneurysm 2. The arrangement of the wires 6 at the end will be discussed in more detail later. That being said, it can probably be specified at this stage that the ends 6a of the wires form a perimeter of the head 5.

According to one aspect of the invention, the braided structure S comprises, at a proximal end of said braided structure S, a knot 4a connected to the head 5. This makes it possible to increase the structural strength of the head 5 during the deployment phase of the intra-aneurysmal device 1 in the carrier artery. The knot 4a makes it possible to stabilize the braided structure S at the head 5, i.e. between the proximal end of the braided structure S and the distal end of said braided structure S, without preventing said head 5 from being movable relative to the knot 4a.

According to an alternative embodiment of the invention, the meshes of the braided structure S at the node 4a are denser than the meshes of the braided structure at the proximal end of the head. The density is defined here as the number of mesh(es) per unit area in arbitrary units. The meshes of the braided structure S are said to be denser because, at said node, they are more numerous per unit area. In other words, the mesh of the braided structure S, at said node 4a, is “fine and tight” as opposed to a loose mesh “wider and relaxed” more likely to deform or lose its structure if no means are provided to preserve it. This configuration is particularly well suited to a device 1 which is provided, in addition to the head 5 and the node 4a, with a proximal portion 3, for example a stent, as we will see below ( Figure 1 ).

According to another variant embodiment of the invention, the braided structure S is formed, at the level of said node 4a, of ends 6c of connected wires, that is to say joined together. This configuration is particularly well suited to an intra-aneurysmal device 1 comprising only a head 5 and a node 4a ( Figure 2 ). Indeed, in this case, the node 4a then connects the plurality of wires 6. In a first configuration, said node 4a can be formed by a crimping ring connecting ends of wires 6c together. Alternatively, in a second configuration, said node 4a can be formed by ends of wires 6c welded together.

In either variant, the node 4a has a cross-section with a diameter D3 much smaller than that of the head 5.

Furthermore, the fact that the knot 4a is connected to the head 5, at the proximal end of said braided structure S, makes it possible to increase the maneuverability of the head 5 and thus reduces the intervention time. Indeed, during the deployment phase, the device 1, which is initially completely inserted into the microcatheter 50, is pushed by a pusher 52 of the microcatheter 50 towards the area to be treated. The presence of the knot 4a thus makes it possible to prevent the device 1 from losing its structural strength under the effect of the stress exerted by the pusher 52 of the microcatheter 50 on said knot 4a and therefore on the head 5 which is in its extension.

According to another aspect of the invention, at the distal end opposite said proximal end of said braided structure S, the head 5 is configured such that at least some of the ends 6a of the wires are parallel and mechanically linked together. This makes it possible to preserve the structural strength of the device 1 during the deployment phase of the intra-aneurysmal device 1 in the carrier artery. Indeed, when the device 1 is inserted into the micro-catheter 50 for the purposes of its deployment and its placement in the area to be treated, it undergoes significant stresses due to the small dimensions of the micro-catheter 50 compared to those of the intra-aneurysmal device 1. Indeed, the internal diameter of the micro-catheter 50 is typically between 0.4 mm and 2 mm. In such a situation, the head 5 undergoes very significant stresses since, being intended to be inserted into the aneurysm 2, it has large dimensions. The connection of certain ends 6a of the wires located at the distal end of the braided structure S makes it possible to improve the structural stability of the head 5 and to preserve the structural strength of the device 1 by avoiding deformation of the head 5 and the separation of the wires 6 from each other.

Furthermore, in this configuration, it is not necessary to allow additional time for filling the aneurysm pocket with coils or with a embolization material as is typically the case in coil and intra-aneurysmal cage devices respectively since the initial structure of the device is preserved after the deployment phase. This reduces the duration of the intervention on the patient.

Preferably, each of said ends 6a of the wires is connected to at least one other of said ends 6a of the wires. In other words, the ends 6a of the wires are mechanically connected at least two by two. The head 5 has the appearance of a water lily having conical petals. In this configuration, the ends being mechanically connected at least two by two, continuously around the entire periphery of the end of the head, the structure of the meshes is preserved. Incidentally, this gives more structural strength to the head 5 and structural stability to the intra-aneurysmal device 1 during the deployment phase.

Preferably, the ends 6a of the wires are mechanically connected to each other by means of a connecting portion 25. The portion 25 extends substantially at the level of the peripheral portion of the wires 6. This is not necessarily exactly the most extreme point of said wires 6 but a portion extending from this point to a peripheral zone of said wires 6. Figures 6a And 6c illustrate such a configuration.

That being said, the connecting portion 25 is not necessarily a point. The connecting portion 25 can also be linear and not punctate. In other words, in such a case the ends 6a of the wires are not mechanically connected to each other at a single point but on a line, or even a cord. Preferably, the length of said connecting portion 25 is between 0.05 mm and 1 mm. The mechanical connection between the ends 6a of the wires is then stronger, and as will be seen later even without the addition of material. Figures 6b And 6d illustrate such a configuration.

Thus, the node 4a being connected to the head 5 and the head 5 being configured such that at least some of the ends 6a of wires located at the distal end of the braided structure S are mechanically linked together on the other hand, the structural stability of the device 1 is preserved during the deployment phase of the device 1 in the aneurysm 2 and the intervention time on the patient is reduced. This advantageously gives the device 1 according to the invention a reduced bulk in comparison with the contour type devices known from the prior art. Indeed, the structural stability of the device is due to the connections existing at the node 4a and at least some of the ends 6a of wires 6 and not to the number of wires. The latter can then be very low.

The intra-aneurysmal device 1 according to the invention can have several configurations depending on whether it is at rest, in the deployment phase or in use. The suitability of the device 1 to move from one configuration to another is due on the one hand to the properties of the material used for its design and on the other hand to its structure based on braided micro-wires. However, as we will see in detail in the following sections, this ability of the device 1 according to the invention to move from one configuration to another does not affect its good structural strength, in particular during the deployment phase.

In reference to the figure 1 , the following describes the configuration of the intra-aneurysmal device 1 according to a first embodiment of the invention at rest, that is to say the configuration of the device 1 in the absence of any pressure on said device 1.

The device 1 according to this first embodiment of the invention may comprise, in addition to the head 5, a proximal portion 3, which is for example a stent. The proximal portion 3, the knot 4a and the head 5 then form the braided structure S.

This particular embodiment involves combining the advantages of the intra-aneurysmal technique and those of conventional stents.

As mentioned above, the braided structure S is made with a plurality of wires 6. The wires 6 are arranged so as to form a plurality of cells of substantially parallelepiped shape. Each cell or mesh comprises a central zone devoid of material, that is to say not covered by the wires 6 and a periphery delimited by the wires 6. The cells are thus said to be “closed”. Depending on the surface area of the cells, the braided structure S is associated with a fine mesh or a large mesh. In this case, a fine mesh comprises cells occupying a smaller surface area compared to a large mesh. It should be noted that, in this particular embodiment, the proximal portion 3, the head 5 and the node 4a can be formed with the same wires 6, which contributes to improving the structural strength of the intra-aneurysmal device 1, but that they do not necessarily have the same type of mesh.

The wires 6 have millimetric longitudinal dimensions and micrometric diametric dimensions. More precisely, the wires 6 have a diameter of between 10 and 500 µm. This diameter is advantageously less than or equal to 50 µm for cerebral aneurysms. That being said, it is approximately 500 µm for thoracic aneurysms. Preferably, the number of wires 6 is between 4 and 250 depending on the dimensions of the device, and therefore the dimensions of the aneurysm and the carrier artery. Even more preferably, the number of wires varies between 16 and 32. Such a number of wires 6 advantageously makes it easier to insert the intra-aneurysmal device 1 into a microcatheter 50 used to deploy the device 1 in the arterial zone affected by the aneurysm. This also provides a braided S structure with sufficient flexibility and maneuverability for insertion in the most difficult to access parts of the body. However, let us specify that the number of wires 6 depends substantially on the diameter of said wires. Thus, if the diameter of the wires 6 is 100 µm, the number of wires cannot exceed 4. On the other hand, if the diameter of the wires 6 is 25 µm, the number of wires can then be much higher, for example 16.

In this regard, the intra-aneurysmal device 1 is advantageously made of a nickel and titanium alloy commonly called nitinol. In addition to the maneuverability offered by this material, it also has excellent shape memory and very good elasticity, which allows it to conform to the morphology of the area in which it is located.

Advantageously, at least one wire is radiopaque. This makes it possible to visualize the wire on a screen, during the intervention, also making it possible to observe the opening state of the device 1.

The proximal portion 3 is suitable and intended to position the intra-aneurysmal device 1 in the carrier artery. In this particular embodiment, the proximal portion 3 has at rest a substantially circular section of diameter D1 suitable for allowing the anchoring/positioning of the intra-aneurysmal device 1 in the artery affected by the aneurysm 2. The proximal portion 3 therefore has a substantially tubular shape.

The node 4a is, for its part, advantageously positioned at an intermediate portion 4 of the device 1. The intermediate portion 4 extends from an upper end 7 of the proximal portion 3 to a base of the head 5. The node 4a has a circular section of diameter, D3, less than the diameter D1 of the proximal portion 3, without this preventing the flow of blood through said node 4a. For example, the diameter D3 of the node 4a can be twice less than the diameter D1 of the proximal portion 3. This allows good transit of the blood flow in the arteries underlying the aneurysm 2.

As mentioned above, the proximal portion 3, the knot 4a and the head 5 are advantageously formed with the same threads 6. However, the mesh of the braided structure S at the knot 4a is narrower. This makes it possible, in addition to the advantages seen above, to avoid the use of an additional tightening means such as a ring.

With reference to the first ( figure 1 ) and second ( figure 2 ) embodiment of the invention, the head 5 has the shape of a concave dome whose concavity 9a is turned outwards. In other words, the head 5 is in the form of a half-sphere or a truncated sphere or a flare or a truncated ovoid turned outwards. The distal end of the head 5 has a substantially circular section, a diameter D2 of which generally increases towards its end. Indeed, at its distal end, the diameter of the head 5 decreases slightly due to the slight inward curvature of the petals. It is at a section located between its distal end and a median part that the diameter D2 of the head 5 is at a maximum. That being said, it remains overall significantly greater in comparison with the diameter at the node, and even with the diameter D1 of the proximal portion 3 for the embodiment illustrated in FIG. figure 1 . Once the device 1 is installed on a patient, the concavity 9a faces the aneurysmal pocket 8 as illustrated in the figure 3 . However, this does not prevent the outline of the free end of the head 5 from being coarse and sinuous, that is to say it is not regular or straight.

At the proximal end of said head, the meshes of the braided structure S are denser than at the distal end of said head, i.e. the meshes are looser. Thus, the meshes of the head 5 have increasing dimensions as they are moved away from the intermediate portion 4, in particular from the node 4a. In other words, at its end, the mesh of the head 5 is therefore much wider than the mesh of the head 5 in the immediate vicinity of the intermediate portion 4. It is also wider than that of the proximal portion 3, of the intermediate portion 4 and therefore of the node 4a. In a particularly advantageous manner, such a mesh also makes it possible to promote a pressing of the head 5 against the walls of the aneurysm 2 when the intra-aneurysmal device 1 is in use, i.e. after deployment. The use of nitinol wires 6 certainly contributes to such plating, but to a much lesser extent, nitinol having a relatively low radial force.

It may also be specified that the mesh of the braided structure S at the head 5 being relaxed, the risk of retraction of the mesh is considerably reduced. Incidentally, this makes it possible to reduce the risk of delayed rupture of the aneurysm 2. Indeed, any retraction of the mesh of the head 5 would have the consequence of leaving a free space between the head 5 and the aneurysm 2 in which the blood could circulate by exerting without any constraint a pressure on the walls of the aneurysm 2, which would ultimately cancel the effects. In addition, the loose mesh at the head 5 makes it possible to substantially increase the flexibility of the head 5, which advantageously makes it possible to treat aneurysms of more varied geometries and dimensions and therefore to treat a greater number of aneurysms.

That being said, the interest of the solution of the invention appears even better taking into account the less dense mesh of the braided structure S at the level of the head 5. Indeed, the fact that the knot 4a is connected to the head 5 stabilizes the mesh at the proximal end of the braided structure, that is to say on the knot 4a side of the head 5. Concomitantly, at the distal end of the braided structure, that is to say on the side of the head 5 opposite the knot 4a, the presence of a connection between certain ends 6a of the threads makes it possible to prevent the initial mesh from being completely altered by the disassembly of the meshes which compose it.

Referring to Figures 2a to 2c, the main phases of deployment of the intra-aneurysmal device 1 are illustrated.

There Figure 3a illustrates the intra-aneurysmal device 1 during the initial phase of deployment. In this configuration, the head 5 is barely visible, the device 1 being almost completely inserted into the micro-catheter 50. The ends 6a of the wires are visible.

There figure 3b illustrates the intra-aneurysmal device 1 during a more advanced phase in the deployment. In this configuration, the intermediate portion 4, the node 4a and the proximal portion are still not visible. The micro-catheter 50 continues to exert pressure on the portion of the head 5 located near the intermediate portion. Nevertheless, the petal-shaped structure resulting from the connection of at least some ends 6a of the wires together is better distinguished.

Disjointed portions 6b of the wires 6 appear less close to each other compared to the configuration they adopt when the device 1 is at rest ( Figure 1 ). Even when subjected to the stress generated by the spacing of the disjointed portions 6b, the connections 25 are preserved. This is explained by the method of connecting the ends 6a of the wires which will be described in more detail below.

In this regard, if some of the ends 6a of the wires are mechanically connected, they must only be so at least during the deployment phase. Indeed, the loss of structural strength is only harmful if it occurs before the head 5 has been able to be correctly positioned within the aneurysm 2. However, it is precisely during the deployment phase that the risk of loss of structural strength is the highest due to the difference in dimensions that exists between the intra-aneurysmal device 1 and the microcatheter 50, which as a reminder has dimensions of between 0.4 and 2 mm. That being said, if the ends 6a of the wires become detached from each other after the deployment of the device 1, this has no impact on the operation of the device 1.

There figure 3c illustrates the intra-aneurysmal device 1 during the final phase of deployment. In this configuration, almost all of the device 1 is deployed. The proximal portion 3, the node 4a and the head 5 are clearly visible. No further pressure is exerted on the head 5 so that it returns to its resting configuration. The structural hold of the head 5 has been preserved since the mesh of the braided structure S is intact at the head 5. This would not have been the case if the node 4a was not connected to the head 5. Indeed, in this case, under the effect of the thrust of the pusher 52 of the micro-catheter, the node 4a and then the head 5 would have undergone deformations. This would also not have been the case if some of the ends 6a of the wires had not been mechanically linked together. Indeed, in this case, under the effect of the thrust of the pusher 52 of the micro-catheter and the pressure exerted by the internal walls of the micro-catheter 50 (as illustrated in FIG. 2b), the mesh of the braided structure S would have disintegrated.

In addition, the proximal portion 3, whose diameter D1 is greater than the diameter of the micro-catheter 50 and on the periphery of which pressures were exerted, also returned to its resting configuration.

It should be noted that other connections may be provided in order to further improve the structural stability of the device 1. The braided structure S may comprise, at certain intersections between the wires 6, connection points 27 at which the wires 6 are mechanically connected. Said connection points 27 are located at one or more appropriate locations in the braided structure S, i.e., at choice in the mesh of the proximal portion 3, the mesh of the intermediate portion 4 or even in the mesh of the head 5. The interest is less with regard to the mesh of the intermediate portion 4 which is advantageously relatively fine. That said, at the level of the proximal portion 3 and the head 5, this can be very advantageous in order to further stabilize the braided structure S during the passage of the device in the micro-catheter 50.

In reference to the figure 4 , the intra-aneurysmal device 1 is illustrated during the final phase of its deployment in an aneurysm 2 reconstituted for the purposes of the tests performed. The reconstituted aneurysm 2 is here made of silicone. The device 1 has retained its initial structure. The head 5 is correctly positioned within the aneurysm 2. It rests on the neck of the aneurysm 2 and its concavity 9a faces the aneurysmal pocket 8. The intermediate portion 4 is, itself, well located at the level of said neck.

In reference to the figure 5 , the result of a numerical simulation of deployment of the intra-aneurysmal device 1 according to the invention is illustrated. These simulations, in particular the simulation illustrated in FIG. 4b, make it possible to better distinguish one end of the proximal portion 3.

The following describes methods 60 for connecting the ends 6a of the wires together.

Let us specify that before implementing this method, the intra-aneurysmal device 1 is provided comprising the braided structure S as described previously with the only particularity that the ends 6a of the wires are not joined.

In reference to the figure 6 , a close-up view of the intra-aneurysmal device 1 according to the invention is illustrated for the purposes of understanding the steps of the method of connecting said ends 6a of said wires together.

In a first step 61, two wires 6 are brought together, the ends 6a of which must be joined so that their ends 6a are substantially parallel.

By bringing the two wires 6 together, a portion of substantially triangular shape is formed, one vertex of which corresponding to a point of rapprochement (which once definitively welded is none other than the connecting portion 25 previously described) of said ends 6a has an angle α (visible on the Figures 6a And 6b ).

Preferably, within the device at rest, the angle α is as closed as possible, that is to say that the angle α is not open. The head 5 can thus be retracted to a minimum during its insertion into the micro-catheter 50 without the connections between the ends 6a of said wires being lost at the same time. Indeed, by securing the ends 6a with an open angle, the radial stresses exerted by the walls of the micro-catheter 50 on the head 5 would cause the ends 6a to become detached before the end of the deployment phase.

In a second step 62, some of the ends 6a are advantageously connected together by means of a fixing method.

Advantageously, this connection can be made by welding the ends 6a without adding material. In this case, the two ends 6a are fused by welding using the material at the ends 6a as the material for the fusion. Welding without adding material makes it possible to reduce the size of the device 1, which facilitates its insertion into the area affected by the aneurysm. Here, the material in question is preferably a nickel-titanium alloy or nitinol. As a reminder, the braided structure S can advantageously be made of nitinol. The advantages of such a material are recalled in the previous sections.

If the connecting portion 25 is in the form of a line or a cord, as mentioned above, two ends 6a of wires are placed in parallel and fused by welding using, as in the configuration described above, the material of the ends 6a. Preferably, this fusion is carried out over a length of between 0.05 mm and 1 mm. Here again, no addition of material is necessary, which allows to improve the strength of the mechanical connection between two ends 6a without increasing the size of the device.

Such welds could for example be implemented using a SweetSpot ^® resonator. Such a device advantageously makes it possible to produce welds smaller than 0.1 mm.

However, the connections at the ends can also be made by welding with the addition of material. In this case, instead of using the material from which the ends 6a are made, the welding is carried out with a supply of molten metal at the point of connection. In this regard, a blue single-strand of 1 to 2 mm can be used.

The third step 63 is a cooling step. Once the solder point is completely cooled, the two ends 6a are permanently bonded. The device is then ready for use.

As a replacement for steps 61 to 63 relating to a welding process, a process for crimping the ends 6a of the wires can also be provided.

Claims (14)

1. Intra-aneurysm device (1) for the treatment of an aneurysm (2), comprising a braided structure (S), with mesh, made with a plurality of wires, the braided structure (S) comprising a head (5) intended to be inserted into the aneurysm (2), the head (5) being able to significantly reduce blood flow in the aneurysm (2), said head (5) having a dome shape, the device (1) being characterised in that the braided structure (S) comprises at a proximal end of said braided structure (S) a node (4a) connected to the head (5), and in that, at its distal end opposite to said proximal end, the head (5) is formed of ends (6a) of wires, at least some of which are mechanically connected together.
2. Device (1) according to claim 1, wherein the wire ends (6a) are mechanically connected at least in pairs.
3. Device (1) according to one of claims 1 or 2, wherein the meshes of the braided structure (S) are denser at the proximal end of said head than at the distal end of said head.
4. Device (1) according to any one of the preceding claims, wherein the head (5) has a substantially semi-spherical geometry facing outwards, the distal end of said head (5) having a substantially circular section of diameter (D2), and the node (4a) having a substantially circular section whose diameter (D3) is smaller than the diameter (D2) of the head (5).
5. Device (1) according to one of the preceding claims, wherein the number of wires is between 4 and 250, preferably between 16 and 32.
6. Device (1) according to any one of the preceding claims, wherein the wires (6) have a diameter of between 10 µm and 500 µm.
7. Device (1) according to any one of the preceding claims, wherein the wires (6) are superimposed at the location of areas (27) of intersection, said wires (6) being mechanically connected at the location of said areas (27) of intersection.
8. Device (1) according to any one of the preceding claims, wherein at least some of the wire ends (6a) are mechanically connected together by means of a connecting portion (25) made of a portion of a first wire (6) and a portion of a second wire (6).
9. Device (1) according to any one of the preceding claims, wherein the wires (6) are made of a biocompatible material, preferably nitinol, platinum or titanium.
10. Device (1) according to any one of the preceding claims, wherein at least one wire (6) is radiopaque.
11. Device (1) according to any one of the preceding claims comprising a proximal portion (3) intended to position the device (1), said node (4a) connecting the proximal portion (3) to the head (5).
12. Device (1) according to any one of the preceding claims, wherein the meshes of the braided structure at the node (4a) are denser than the meshes of the braided structure at the proximal end of the head.
13. Device (1) according to one of claims 1 to 11, wherein said node (4a) is formed by a crimping ring connecting wire ends (6c) together.
14. Device (1) according to one of claims 1 to 11, wherein said node (4a) is formed by wire ends (6c) welded together.

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